Yeah, perhaps your right. It just seemed weird to me that a brand new account bidder would be leading at $300.00 and raise it to $400.00, but perhaps the reserve wasn't met yet at $300.00.
Yes, that pretty much HAS to be what happened. Since no one else bid in between, you wouldn't be able to see a higher number unless some threshold (outbid someone or hit the reserve) was reached. You can't up your 'winning' bid just by bidding again, you'd need a second bidder.
I suppose a shill bidder isn't out of the question, but in my mind it's just as likely to be someone who's not used ebay before, but was told to go there to find a machine.
My defense against shill bidding is to not get caught up in the bidding. I bid early, I bid what I'm willing to pay, and I leave it alone. My theory is that people using shill bidders tend to think an early bidder can be prodded into bidding again and thus over-paying. I don't bite, so I don't have reason to think I've been bitten by shills.
This also works great against bid snipers. I've bid exactly what I am willing to pay. If you want to pay more, whether it's moments after I bid or moments before auction close, you have fun with that. Trying to out-do me by bidding 10 cents over my current bid in the last seconds won't really matter much one way or the other.
I should also say, if it is a shill, it's a stupid one. Shill bidding to get the bid up over the reserve isn't doing the seller any favors. Now he's out even more fees if it doesn't sell, AND since he's jumped quite a bit over the previous bidders, it's not necessarily going to get more bids (it might, but it might not).